Bladder Meridian
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BL-34
Needle Depth
0.8–1.2 cun
Needle Angle
90° (Perpendicular)
Body Area
Back — Sacral
Location
In the 4th posterior sacral foramen, between the posterior superior iliac spine and the midline.
Main Actions
- Regulates the Lower Burner and facilitates urination and defecation
- Resolves Dampness and regulates menstruation
- Benefits the lower back and legs
Indications
Diarrhoea
Borborygmi
Leukorrhea
Sacrum pain
Coccyx pain
Lumbar pain
Constipation
Vaginal pain
Bloody stools
Shan disorder
Testicle pain
Painful period
Genitalia pain
Painful urination
Genitalia itching
Genitalia swollen
Urinary difficulty
Lower abdominal pain
Defecation difficulty
Commentary
'Liao' means crevice, thus BL-31, BL-32, BL-33 and BL-34 are called 'Siliao'(Four crevices) or 'Baliao'(Eight crevice since there are four crevices on each side). They are called so, due to their location in the four sacral foramina.
Shangliao BL-31 (Upper crevice) is at the highest sacral foramina. Ciliao BL-32 (Second crevice) is at the second. Zhongliao BL-33 (Middle crevice) the third, while Xialiao BL-34 (Lower crevice) is the last one.
All these four points share similar actions.
First of all, BL-34 regulates the Lower Burner and treats urination and defecation difficulties. Kidney Deficiency is an important underlying pattern for this disorder, which is frequently seen in elderly and weak patients. Typical urinary manifestations include painful and difficult urination, dark and retention of urine and enuresis. While intestines related symptoms covers difficult defecation, constipation, borborygmi and diarrhoea. BL-34 has the widest action on the intestines.
Furthermore, by removing Dampness from the Lower Burner, the point is effective in treating gynecological disorders such as dysmenorrhea, infertility, irregular menstruation, labor pain and leucorrhoea. Xialiao BL-34 has the strongest effect.
BL-34 also has the strongest effect on solving genital disorders. Typical manifestations are swelling and painful vagina, incessant green vaginal discharge, pain of the testicles and etc.
All these four points benefit the lumbar region, lower back and legs. They remove the Painful Obstructions from the Channel by invigorating the Qi and Blood.
Classical Sources
Ling Shu (Spiritual Pivot): The ancient text mentions the Baliao points in context of treating lower back pain and disorders of the lower body.
Su Wen (Plain Questions) - Bone Hollow Treatise: "For lumbar pain that cannot turn or rotate, radiating to the genitals, needle the Baliao (Eight Liao) and above the painful area; the Baliao are in the eight spaces at the waist and sacrum."
Zhen Jiu Da Cheng (Great Compendium of Acupuncture and Moxibustion): "The Baliao together treat lumbar pain." This classic established the importance of these sacral foramen points for lower back and pelvic disorders.
How to Locate
First identify the Tuffier's line which connects the highest points of the iliac crest. The spinous process of the 4th lumber vertebra (L4) mostly falls on this line. Then palpate in an inferior direction, passing L5, and reach the most superior sacral spinous foramen. Palpate further to reach the 4th foramen, where Xialiao BL-34 is located. Here is to identify the 4 sacral foramens and the corresponding points at the same time. First locate the 4th sacral foramen on the level of the superior end of the rima ani (sometimes a bit more superiorly or inferiorly). Place the little finger on the 4th foramen, then the ring, middle and index fingers on a slightly V-shaped line in a superior direction, palpating for the depressions of the sacral foramens. With the fingers in this position, the index finger will be resting on Shangliao BL-31 of the 1st foramen, the middle finger on Ciliao BL-32 of the 2nd foramen, the ring finger on Zhongliao BL-33 of the 3rd foramen and the little finger on Xialiao BL-44 of the 4th foramen.
Caution
Pregnancy caution: Reducing needling techniques are contraindicated during pregnancy, except when specifically used for promoting labor. Deep insertion through the sacral foramen requires careful technique to avoid excessive stimulation. Practitioners should be aware of the proximity to sacral nerves (S4) when needling deeply.
Needle Angle
90° (Perpendicular)
Depth Category
Medium
Standard Depth
0.8–1.2 cun
Needling Directions
Vertically 0.7–1 cun. Or 1.5-2 cun through the foramen. Caution:Reducing Needling techniques are contraindicated during pregnancy, except for promoting labor.
Expected Deqi Sensation
Deqi sensation typically manifests as local distension and soreness at the sacral region. With deeper insertion (1.5-2 cun through the sacral foramen), the sensation may radiate to the lower abdomen, perineum, genital area, or down the posterior leg. Some patients experience warmth spreading through the pelvic region.
Moxibustion
Recommended
Duration: 10–15 minutes
Cupping
Recommended
Bloodletting
N/A
Gua Sha
Recommended
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